/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2016 Olaf Wintermann. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file avl.h
*
* AVL tree implementation.
*
* This binary search tree implementation allows average O(1) insertion and
* removal of elements (excluding binary search time).
*
* @author Mike Becker
* @author Olaf Wintermann
*/
#ifndef UCX_AVL_H
#define UCX_AVL_H
#include "ucx.h"
#include "allocator.h"
#include <inttypes.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* UCX AVL Node type.
*
* @see UcxAVLNode
*/
typedef struct UcxAVLNode UcxAVLNode;
/**
* UCX AVL Node.
*/
struct UcxAVLNode {
/**
* The key for this node.
*/
intptr_t key;
/**
* Data contained by this node.
*/
void *value;
/**
* The height of this (sub)-tree.
*/
size_t height;
/**
* Parent node.
*/
UcxAVLNode *parent;
/**
* Root node of left subtree.
*/
UcxAVLNode *left;
/**
* Root node of right subtree.
*/
UcxAVLNode *right;
};
/**
* UCX AVL Tree.
*/
typedef struct {
/**
* The UcxAllocator that shall be used to manage the memory for node data.
*/
UcxAllocator *allocator;
/**
* Root node of the tree.
*/
UcxAVLNode *root;
/**
* Compare function that shall be used to compare the UcxAVLNode keys.
* @see UcxAVLNode.key
*/
cmp_func cmpfunc;
/**
* Custom user data.
* This data will also be provided to the cmpfunc.
*/
void *userdata;
} UcxAVLTree;
/**
* Initializes a new UcxAVLTree with a default allocator.
*
* @param cmpfunc the compare function that shall be used
* @return a new UcxAVLTree object
* @see ucx_avl_new_a()
*/
UcxAVLTree *ucx_avl_new(cmp_func cmpfunc);
/**
* Initializes a new UcxAVLTree with the specified allocator.
*
* The cmpfunc should be capable of comparing two keys within this AVL tree.
* So if you want to use null terminated strings as keys, you could use the
* ucx_strcmp() function here.
*
* @param cmpfunc the compare function that shall be used
* @param allocator the UcxAllocator that shall be used
* @return a new UcxAVLTree object
*/
UcxAVLTree *ucx_avl_new_a(cmp_func cmpfunc, UcxAllocator *allocator);
/**
* Destroys a UcxAVLTree.
* @param tree the tree to destroy
*/
void ucx_avl_free(UcxAVLTree *tree);
/**
* Macro for initializing a new UcxAVLTree with the default allocator and a
* ucx_ptrcmp() compare function.
*
* @return a new default UcxAVLTree object
*/
#define ucx_avl_default_new() ucx_avl_new_a(ucx_ptrcmp, ucx_default_allocator())
/**
* Gets the node from the tree, that is associated with the specified key.
* @param tree the UcxAVLTree
* @param key the key
* @return the node (or <code>NULL</code>, if the key is not present)
*/
UcxAVLNode *ucx_avl_get_node(UcxAVLTree *tree, intptr_t key);
/**
* Gets the value from the tree, that is associated with the specified key.
* @param tree the UcxAVLTree
* @param key the key
* @return the value (or <code>NULL</code>, if the key is not present)
*/
void *ucx_avl_get(UcxAVLTree *tree, intptr_t key);
/**
* Puts a key/value pair into the tree.
*
* Attention: use this function only, if a possible old value does not need
* to be preserved.
*
* @param tree the UcxAVLTree
* @param key the key
* @param value the new value
* @return zero, if and only if the operation succeeded
*/
int ucx_avl_put(UcxAVLTree *tree, intptr_t key, void *value);
/**
* Puts a key/value pair into the tree.
*
* This is a secure function which saves the old value to the variable pointed
* at by oldvalue.
*
* @param tree the UcxAVLTree
* @param key the key
* @param value the new value
* @param oldvalue optional: a pointer to the location where a possible old
* value shall be stored
* @return zero, if and only if the operation succeeded
*/
int ucx_avl_put_s(UcxAVLTree *tree, intptr_t key, void *value, void **oldvalue);
/**
* Removes a node from the AVL tree.
*
* Note: the specified node is logically removed. The tree implementation
* decides which memory area is freed. In most cases the here provided node
* is freed, so it's further use is generally undefined.
*
* @param tree the UcxAVLTree
* @param node the node to remove
* @return zero, if and only if an element has been removed
*/
int ucx_avl_remove_node(UcxAVLTree *tree, UcxAVLNode *node);
/**
* Removes an element from the AVL tree.
*
* @param tree the UcxAVLTree
* @param key the key
* @return zero, if and only if an element has been removed
*/
int ucx_avl_remove(UcxAVLTree *tree, intptr_t key);
/**
* Removes an element from the AVL tree.
*
* This is a secure function which saves the old key and value data from node
* to the variables at the location of oldkey and oldvalue (if specified), so
* they can be freed afterwards (if necessary).
*
* Note: the returned key in oldkey is possibly not the same as the provided
* key for the lookup (in terms of memory location).
*
* @param tree the UcxAVLTree
* @param key the key of the element to remove
* @param oldkey optional: a pointer to the location where the old key shall be
* stored
* @param oldvalue optional: a pointer to the location where the old value
* shall be stored
* @return zero, if and only if an element has been removed
*/
int ucx_avl_remove_s(UcxAVLTree *tree, intptr_t key,
intptr_t *oldkey, void **oldvalue);
/**
* Counts the nodes in the specified UcxAVLTree.
* @param tree the AVL tree
* @return the node count
*/
size_t ucx_avl_count(UcxAVLTree *tree);
#ifdef __cplusplus
}
#endif
#endif /* UCX_AVL_H */